Abstract The Biostatistics Core provides a broad array of statistical services in support of the three Projects and other three Cores. The Core will provide regular advice on Experimental design, such as selection of end points, sample size and power, and optimal use of animals. The Core is responsible for all clinical data management as it relates to the Blood and Marrow Transplant Program in a secure central location. The Core will perform expert statistical analyses in a format consistent between Projects using techniques that are state of the art in practice. The Core will also facilitate data sharing with the Program as well as the general scientific community. The Core is staffed by experienced biostatisticians who have daily working relationships with the Project investigators. The Core biostatisticians have been an integral part in the development of the Program and have participated in this PPG for most of its history. The Core has access to all needed software. This dedicated Biostatistics Core provides easy access to Program investigators and has allowed biostatisticians to specialize in the specific Project areas, gaining working knowledge in the field helping provide the tailored biostatistical support.